Boring or surfacing tool holder



Dec. 19, 1922. 1,439,190

H. P. PRITCHARD. BQRlNG 0R SURFA ING Toor. HoLm-:R'A

FILED DE 2A 1919A l i z3 :In M I@ Patented Dec. 19, 1922.

Narreso ,l sTATS i iwiiitn r. Terroristen, or'crinvnminn 'o1-no.

Bosrncfoafsuemrcmeweer*Houma Y To alleato/mit meyfcoaeem: ,A

BeV it known',that-,Y Homann 'P.- PRrroHARD, a citizen of the UnitedStates, residingfat Cleveland, in -`th'e'county ofk Cuyahoga and State yof QhiO,y have invented'certain new Y and useful improvements in Boring or Surfacing 'llcol Holders, ofy which theifdllowing is afspeciiicatiom s This -inventioniirelatesfto a device for use in connectionA witlrdrill presses, -verticalboring millsrmillingiv machines j and4 the like, it is particularly :adapted for f boring out cored openings to their =truesize and,.\owing to "its particular :construction is; adapted for use in die work Whensurfacngandcbttoming, or limshing therfbcttoms Lof cored Aopeninv's. e

particular advantage .gained-by `the yuse of `this tool is in the adjustability. The device as yshown beingfcapablerof drilling, and

' boring hol'esfrom theismallestrsizeto several inches and further,1aiidtheiconstructionfperr mits the tool tobeadvanced' for successive longk distances oroverfvery -minutefonesl with i each adjustment, thefdistance: of ytravelxibeing Aaccurately -determined -l bythe employment of a graduated dial" to indicate the movement there0f. h e

Further objects fofy the invention are 1n the provision of meansfor ipositioninga tool eccentric with respect to the axis of the machine spindle for the purpose of enlarging an opening initially made for the tool such y as a cored opening and the provision of a tool which kwill be composed 4of a minimum number of parts so arranged as to provide a simple, eiiicient and very durable construction, and the provision of means for so holding the cutting tool as to permit of using one with an extremely short shank, ypreventing any possibility yof the tool breaking or vi-.

brating.

Vith the foregoing and other objects" in mind the invention consists of the novel construction and combination of parts hereinafter described, illustrated in the accompanying drawings and pointed' out in the appended claims, reference being had to the accompanying drawings wherein like reference numerals designate similar parts of reference throughoutv the Various views, F ig. 1 is a plan view of the device; Fig. 2

is a-central longitudinal section on line 2 2k of Fig. y1; Fig. 3 is an Lend elevation as viewed from the right of Fig@ `and Figs. and 5 'are sectional details taken on the-corresponding-lines of lFig. Q.

lhe device as shown; comprises a base l provided with a .dove-tailed Vslide-way 2 and aninternally threaded boss 8 whereby the device maybe applied tothespiudle of the actuatingsmachine.v Thefbody lis provided atene-'end witha vertical extension -or ear` provided with a bore 5 intofwhi'chy is rotatably rmounted a bushing 6-which is threaded to receive the screw 1l which `iswrigidly held inthe bushing-by the knuts 12 and 14 on the-screw, the bushing: being-'held in the ear bythe nut 7 on thethreaded end effflhe y bushing, kwhich fnut ican be l adj ustely to take 11p-wear. The bushing supports a cellar which is provided withgraduatiors 9. This collar is free to rotate'labout Itheibushing and `is ylocked thereon after the proper adjustment has been obtained, by the set screw 10. The bushing is free tofrota'te within the `year 4 and-is itself-provided with abore through which is :passed a lead-screw 11, and said screw may be lockedagainst further rotation ywithin the bushing (i4r by lock` nuts 14k-andi?. A star wheell is fixed on the'endo'f the screw 1-1 between the nuts lf2-and 14. Mounted lwithin the dove-tailed guideway 2viis alsocke't piecewcomprisiug a movable head 15 and said head is provided with a squared opening 1G within which is placed the cutting tool 17.' This socket piece is preferably made cylindrical to permit of insertion within a previously made opening inthe material to be machined and due to ythis construction a cutting` tool with a very short shank is permitted to be used, this feature effectively eliminates the possibility of breakage of the tool and prevents the same froln vibrating or chattering. This tool may be of any desired shape or form and is secured within the opening 16 by means of the set screws 18 which are threaded within the head 15.

by the main "frame ol the actuating machine, one form thereo't' being indicated in dotted lines at of Fig. 2, and thus upon each rotation of the tool the lead-screw 11 and its bushings G are given one quarter or other turn according to the number ol", arms on the star Wheel, Whieheauses the head l5 `to be moved Within they aforementioned guideways This method is employed only 1n surtacing or m bottommg and permits a spiral cut to be had, each succeeding cut of which will be upon the same plane, and

in this manner the device may be used upon a drill press5 lathe or milling machine and produees yresult equal tothat obtained by the use of eithera Shaper or planer. lWhen the device is to be used ior boring ina lathe or boring;` mill, or an)7 time 'when a helicil eut is to be obtained, it is vevidentthat the' serein' li is merely for the purpose of ad-A justment and by the use of `the index collar 8 this maybe determined very accurately. 1When used in surfacing and when it de# sired to ldetermine the depth of ay vut ue-v curately, say one-tenth o't an inch, the collar is set at Zero and then the bushing and screw are turned until the eollar indicates an'advance 'of one-tenth of an inclnbjj; re-l lation to the index on the ear Then the tool Will start to out a tenth of an ineh deep, and then it' it is desired to cut another tenti ot an inchftherollar is set bari: to zero and .toward and, from said bearino that which comes Within the scope ot the aforesaid claims.

l claim: y j n l. A; tool holdercomprismg a base having` a bearing', atool socket slidable on the base b, a screw threaded into said socket to adjust the same,

bushingrotatably mounted in the bearing,

said screw extending through the bushing, nuts on the se1eW-,^clamped against opposite ends of the bushing, means to rotate the screw and bushing` `and ralgraduated collar rotatably mounted yon the bushing' and eooperating Witlran indexen the bearings.

2. A to'ol holder comprising a base yhaving bearing` ear, a tool socketv slidableon the base-toward and,roinsaid-ear, a screw.

threzftdedxinto. said soele to adjust the saine7 a bushing lixed to the serewand rotatably mounted in said bearing` ear, and a graduated collar rotatably mounted on .the busliing` for adjustment around the same and cooperating with an index on thev ear to indicate the settingot the screw. m

A .tool holder comprising' a baste hav-x ing` 'abearing ear. a vtool soclrrtshdable onk the base toward and rom said ear, a sorev threaded into said socket to adjust the same, a bushing fixed to thesorew and rotatably mounted 1nv said bea-ring ear, and a graduated collar rotatablyy mounted on the jbushing-'igor adjustment around the' same and (cooperating'with anrindex on the ear to indicato the sottmgot' the screw7 saldeollar beingy provided with'. meansto .fasten the same to the bushing. Y

In testimony Whereofylvdo affix my site nature ui presence, ot two witnesses. lx

HOWARD i?. riu'rou'iiuu lllitnesses: .l

JOHN A. B oMuHAiuyr,` ROBERT L. Bri-UCK. 

